knnleow on "Multiple 'X-Frame-Options' headers with conflicting values ('SAMEORIGIN, DENY')"

any advice on this issue i encountered while trying to import my wordpress xml backup from another server.

this used to work when Self Signed SSL Cert was used. i now install Letsencrypt SSL and import seem to fail now.

i did the recommended setting in the nginx "default" file to allow SAMEORIGIN, but still not able to get import.php to run.

this is the export import source and destination.
export from: https://knnubt05oc.kuenn.co:443
import to: https://knnubt05oc.kuenn.co:49086
Note that i am using the same Letsencrypt Cert as the servers are the same ipAddress.

below is error seem by inspect (both google and firefox show same error)

Multiple 'X-Frame-Options' headers with conflicting values ('SAMEORIGIN, DENY') encountered when loading 'https://knnubt05oc.kuenn.co:49086/wp-admin/plugin-install.php?tab=plugin-information&plugin=wordpress-importer&from=import&'. Falling back to 'DENY'.

Refused to display 'https://knnubt05oc.kuenn.co:49086/wp-admin/plugin-install.php?tab=plugin-information&plugin=wordpress-importer&from=import&' in a frame because it set 'X-Frame-Options' to 'SAMEORIGIN, DENY'.

`Uncaught SecurityError: Failed to read the 'contentDocument' property from 'HTMLIFrameElement': Sandbox access violation: Blocked a frame at "https://knnubt05oc.kuenn.co:49086" from accessing a frame at "https://knnubt05oc.kuenn.co:49086". The frame being accessed is sandboxed and lacks the "allow-same-origin" flag.

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